CFA Best Practices for Application Questions and Answers 1 — Questions and Answers
Question 1: The 4R Nutrient Stewardship framework is a cornerstone of best practices for fertilizer application. What are the four "rights" that comprise this framework?
- Right Regulation, Right Test, Right Equipment, Right Price
- Right Source, Right Rate, Right Time, Right Place (Correct answer)
- Right Crop, Right Season, Right Weather, Right Soil
- Right Spreader, Right Tractor, Right Field, Right Form
Correct answer: Right Source, Right Rate, Right Time, Right Place
The 4R Nutrient Stewardship concept provides a globally recognized framework for achieving cropping system goals by managing plant nutrients responsibly. The four core components are applying the Right Source of nutrients at the Right Rate, at the Right Time, and in the Right Place.
Question 2: An applicator is applying granular phosphorus fertilizer to a field that slopes gently towards a stream. To best protect water quality from nutrient runoff, which of the following actions is most critical?
- Applying the fertilizer in the middle of the day when the sun is brightest.
- Increasing the application rate by 10% to account for potential losses.
- Maintaining a mandatory or voluntary vegetated buffer strip where no fertilizer is applied. (Correct answer)
- Calibrating the spreader to throw fertilizer into the water to feed aquatic plants.
Correct answer: Maintaining a mandatory or voluntary vegetated buffer strip where no fertilizer is applied.
Maintaining an unfertilized, vegetated buffer strip or setback from surface water bodies is a key best management practice. This strip helps to filter runoff and absorb nutrients before they can enter the stream, protecting water quality from contaminants like phosphorus. The other options are incorrect and could potentially worsen the environmental impact.
Question 3: A farmer is growing corn on a silt loam soil in a region that receives significant spring rainfall. To maximize nitrogen use efficiency and minimize the risk of leaching or denitrification, which nitrogen application strategy is most advisable?
- Applying a smaller portion of nitrogen at or near planting, and the majority as a sidedress application when the corn is actively growing. (Correct answer)
- Applying the full amount of nitrogen as anhydrous ammonia in the fall before planting.
- Broadcasting the entire nitrogen requirement as urea on the soil surface one month before planting.
- Applying all the nitrogen as a liquid UAN solution immediately after the corn has been harvested.
Correct answer: Applying a smaller portion of nitrogen at or near planting, and the majority as a sidedress application when the corn is actively growing.
A split application, or sidedressing, synchronizes the application of the majority of the nitrogen with the period of maximum uptake by the corn crop. This approach reduces the amount of time the nitrogen is in the soil before the crop needs it, thus minimizing the potential for environmental losses through leaching or denitrification, especially in wet conditions.
Question 4: Which of the following is a primary agronomic advantage of banding a phosphorus (P) fertilizer near the seed row, especially in cool, low-testing soils?
- It encourages deep root growth by forcing roots to search for nutrients.
- It concentrates the immobile nutrient in a zone where it is more accessible to young plant roots. (Correct answer)
- It increases the risk of salt injury to the germinating seed.
- It guarantees that the nutrient will not be lost to volatilization.
Correct answer: It concentrates the immobile nutrient in a zone where it is more accessible to young plant roots.
Phosphorus is relatively immobile in the soil. Banding concentrates the P fertilizer in a specific zone close to developing roots, increasing the likelihood of root interception and uptake. This is particularly effective for promoting early-season growth in cool soils where nutrient availability and root growth are limited.
Question 5: An applicator surface-broadcasts urea (46-0-0) on a warm, moist, high-residue field. What is the most significant potential pathway for nitrogen loss if the urea is NOT incorporated into the soil shortly after application?
- Denitrification
- Leaching
- Surface runoff
- Volatilization (Correct answer)
Correct answer: Volatilization
When urea is applied to the soil surface, it is converted to ammonium by the urease enzyme. This process can lead to the formation of ammonia gas, which is lost to the atmosphere. This pathway, known as volatilization, is most significant in warm, moist conditions. Incorporating the urea via tillage or rainfall places it in the soil where the ammonium can be held, preventing this loss.
Question 6: According to best management practices, which of the following pieces of information is LEAST critical to include in a fertilizer application record for a specific field?
- The date and time of the application.
- The fertilizer analysis and rate applied.
- The color of the tractor used for the application. (Correct answer)
- The weather conditions, including wind speed and direction.
Correct answer: The color of the tractor used for the application.
While a company might track equipment internally, the color of the tractor has no agronomic or regulatory importance for a fertilizer application record. Essential records must include what was applied (analysis), how much (rate), where (field ID), when (date/time), and the environmental conditions at the time of application (weather) to ensure accuracy, support agronomic decisions, and maintain regulatory compliance.
CFA Best Practices for Application Questions and Answers 1
The 4R Nutrient Stewardship framework is a cornerstone of best practices for fertilizer application.
What are the four "rights" that comprise this framework?